Devices for recording information using magnetic domain structures in a magnetic wire have been proposed. In recent years, it has been found experimentally that positions of magnetic domain walls can be changed by a current. Realization of magnetic memories using magnetic wires is now expected. The term “domain wall” means a boundary between magnetic domains having different magnetization directions.
A magnetic domain wall in a magnetic wire can easily be moved by applying, for example, a magnetic field thereto externally if its constituent materials are in an ideal state in terms of uniformity and shape. Therefore, to use a magnetic wire to form a magnetic memory, means that fixes a magnetic domain wall at an intended position is necessary. On the other hand, if the position of a magnetic domain wall is fixed too strongly, a large drive current is necessary to move it. This may make it impossible to design a magnetic memory that is functional. In view of this, a method for controlling domain wall motion in a magnetic wire by dynamically changing magnetic energy with respect to a magnetic domain wall using an electric field has been proposed. However, it is difficult to control domain wall motion with high accuracy using an electric field because the magnetic energy may be rendered unstable.